It's bad enough for some propeller planes to be referred to as being powered by elastic band. Now the skeptics could begin having a dig at commercial aircraft flying on whatever from cooking oil to liquefied algae.

With the civil air travel industry under increasing pressure from increasing oil prices and environmental legislation, the race is on to find practical alternatives to traditional kerosene and these so far seem to come down to numerous types of biofuel.

Not surprisingly, the first trials of alternative fuel were initiated by British air travel leader, Sir Richard Branson, whose Virgin Atlantic started London to Amsterdam flights with limited biofuel usage in 2008. This was quickly followed by Lufthansa and Air New Zealand who each utilized different blends of regular fuel and bio derivatives including some from made from jatropha which can grow in soil thought about too poor for growing mainstream foodstuffs.

Jatropha is a genus of approximately 175 succulent plants, shrubs and trees (some are deciduous, like Jatropha curcas), from the household Euphorbiaceae.

In 2007 Goldman Sachs cited Jatropha curcas as one of the best candidates for future biodiesel production. It is resistant to dry spell and bugs, and produces seeds consisting of 27-40% oil.

Recently, US aerospace giant Boeing, Brazilian aeronautical significant Embraer and the Sao Paulo state Research Support Foundation moved to perform research and advancement into the usage of biofuels to power jet airliners. It was reported that Brazilian airlines Azul, Gol, TAM and Trip would function as strategic consultants for the job.

The current airline company to begin explore new fuels is the Alaska Air Group which has actually conducted internal US flights utilizing a mix of 80 % petroleum based fuel and 20% biofuel made from cooking oil. This mixture, it is declared, can cut hazardous emissions by 10%.

One actually encouraging advancement has been the move away from biofuels which complete head on with food customers consequently preventing a cost spiral. Not so long ago, a rise in usage of biofuels in vehicles triggered a spike in maize costs as US farmers diverted excessive corn to fuel processing.

Hopefully in the future, airlines and drivers will focus biofuel intake on non-food sources such as jatropha and algae. It would be a blended blessing certainly if some people wound up starving simply to please someone else's green credentials.